Keep your controllers clean and forms flexible by adding virtual attributes to your model. This very powerful technique allows you to create form fields which may not directly relate to the database.
(3 minutes)

You can pass more than simple strings to find conditions. Arrays, ranges, and nil values can be passed as well. In this episode you will see the tricks involved with passing these odd objects to find conditions. (Update: audio fixed).
(4 minutes)

Be careful when storing a model in a session. It will behave differently than you expect and can easily get out of sync with the database. Instead of storing the model directly in the session, store the id to the model and use that to fetch it from the database.
(5 minutes)

Testing and refactoring go hand in hand. Refactoring is all about improving code without changing its behavior. Testing is all about making sure you don't change the behavior while you are improving the code.
(6 minutes)

Are you accepting sensitive user data? Passwords, credit card numbers, etc. By default, Rails stores all submitted parameters in plain text in the logs. This episode will show you how to filter this sensitive input so it doesn't show up in the log file.
(2 minutes)

Everything you wanted to know about layouts: global layouts, controller layouts, shared layouts, dynamic layouts and action layouts. Yes, there really are that many ways to specify a layout.
(6 minutes)